Methods and apparatuses for enabling cell activation in a network

ABSTRACT

The embodiments herein relate to a method performed in a terminal, a terminal, a method performed in a network node and a network node, for supporting activation of a cell. The terminal is configured to receive a message form the network node and if the message comprises an indicator indicating whether the UE shall perform activation of the cell, the UE activates the cell upon configuration of the cell.

TECHNICAL FIELD

The technology described herein relates to a user equipment or terminal,a method thereof for enabling cell activation in a network, a networknode and method thereof for enabling cell activation in the network.

BACKGROUND

Long Term Evolution (LTE) specifications from the 3^(rd) GenerationPartnership Project (3GPP) support component carrier bandwidth up to 20MHz. However, in order to meet the International MobileTelecommunications Advanced (IMT-Advanced) requirements for (very) highdata rates, the concept of carrier aggregation has been introduced tosupport bandwidths larger than 20 MHz. The carrier aggregation conceptis illustrated in FIG. 1, where five component carriers, or cells, areillustrated, with 20 MHz of bandwidth each. In the example of FIG. 1,the total bandwidth available to a mobile terminal is the sum of thebandwidths of the cells, i.e. 100 MHz.

Note that in the context of carrier aggregation, a component carrieralso refers to a cell. Hence five components carriers as illustrated inFIG. 1 correspond to five cells.

A terminal or a user equipment (UE) may be configured with a subset ofthe cells offered by the network and the number of aggregated cellsconfigured for one terminal or UE may change dynamically through timebased on for example terminal traffic demand, type of service used bythe terminal, system load etc. A cell which a terminal is configured touse is referred to as a serving cell for that terminal. A terminal hasone primary serving cell (called PCell) and zero or more secondaryserving cells (SCells), the term serving cell includes both the PCelland SCells. Which cell is a terminal's PCell is terminal-specific. ThePCell is considered more important and for example some controlsignaling is handled via the PCell. Hence in case of five componentscarriers as shown in FIG. 1, the terminal may have one PCell and zero,one, two, three or four SCells. As mentioned some control signalling ishandled via the PCell and therefore the PCell is an important carrierfor the terminal.

Aside from that the concept of configuration of cells/carriers has beenintroduced the concept of activation has been introduced for SCells (notfor the PCell). Cells may be configured (or deconfigured) using RadioResource Control (RRC) signaling, which can be slow, and at least SCellscan be activated (or deactivated) using a Medium Access Control (MAC)control element, which is much faster. Since the activation process isbased on MAC control elements—which are much faster than RRCsignaling—an activation/de-activation process can quickly adjust thenumber of activated cells to match the number that are required tofulfil data rate needed at any given time. Activation therefore providesthe possibility to keep multiple cells configured for activation on anas-needed basis.

When a terminal or UE gets configured with a cell it may need to re-tunethe radio frontend (RF) to cover the spectrum of the configured cell andto change the carrier frequency. Similarly, when a serving cell isdeconfigured the terminal may need to re-tune the radio frontend so asto not cover the deconfigured cell. As a consequence of radio frontendre-tuning the terminal may need to perform an interruption, or glitch,during which the terminal is not able to receive of transmit signalsusing that radio frontend. An example is shown in FIG. 2 and FIG. 3. Inthe example of FIG. 2 the terminal is configured with Cell A and Cell Bbut not Cell C. This is indicated by “covered spectrum”.

In FIG. 3, the terminal is configured with all 3 cells A, B and C. Whenalso Cell C is configured the terminal may need to perform a radiofrontend re-tuning and hence perform a glitch or interruption. Similarlywith deconfiguration, if the terminal cell configuration is first as inFIG. 3 but at a later stage Cell C is deconfigured the terminal mayretune the radio frontend to enter the configuration as in FIG. 2.

When a cell/carrier is activated or deactivated the terminal may alsoperform a glitch, similar to the case of configuration ordeconfiguration.

Hence, in order for a terminal to be able to use a cell fortransmission, the cell first needs to be configured for the terminal.Cell configuration may be handled on RRC level and the network or thenetwork node is configured to send to the terminal a RRC messageordering the configuration of the cell. The terminal is required toexecute the order within a delay referred to as RRC processing delay,which currently is specified to be 20 ms in case for cell configuration.After the 20 ms has passed and the terminal has performed the cellconfiguration, the terminal responds to the network or network node bysending an RRC message indicating that the configuration is complete.

When the network or network node has received the RRC message from theterminal indicating that the cell configuration is complete the network(node) can send to the terminal an order for activation of the cell. Theterminal is required to execute the order for activation within a timeperiod e.g. 8 ms, after which the terminal is configured to respond tothe network node with an acknowledgement of the activation command. Thisdelay is referred to as activation delay in this disclosure.

It should be noted that in case the new cell has an uplink configuredand the terminal has no valid TA (Timing Advance) value for the new cellthe terminal may need to perform a random access procedure to get avalid TA value for the new cell.

So the total time it takes to get a currently not configured cell readyfor communication for a terminal is:

(Scheduling delay of cell configuration message)+(RRC processingdelay)+(Scheduling delay for activation order message)+(activationdelay)+(Scheduling delay for random access procedure ordermessage)+(time for random access procedure)

If this total time is long it will negatively affect the user experienceand network performance.

It is currently discussed in 3GPP if it is necessary to extend theactivation delay. However, an extension of the activation delay leads tothat the total time above becomes longer. The reason for doing so wouldbe that the terminal may need to perform a glitch, or interruption, dueto RF tuning upon cell activation during which the terminal may not beable to communicate with the network on some, or all, cells. So not onlywould the delay for enabling communication on a cell be extended butalso it could possibly effect the communication between the terminal andthe network on other cells/carriers. This would further degrade userexperience and the network performance.

SUMMARY

It is therefore an object of the exemplary embodiments herein to obviateat least the problems mentioned above.

According to an aspect of the present embodiments, there is provided amethod performed in a user equipment (UE) for enabling activation of acell (or carrier). The method comprising: receiving a message from anetwork node; determining if the received message contains an indicatorindicating whether the UE shall perform activation of the cell uponconfiguration and, that being the case, activating the cell uponconfiguration of the cell.

According to another aspect of the present embodiments, there isprovided a method performed in a network node for enabling activation ofa cell (or carrier). The method comprising: deciding if a UE shallperform activation of a cell upon configuration and, that being thecase, signaling a message to the UE, the message containing an indicatorordering the UE to activate the cell upon configuration of the cell.

According to yet another aspect of the present embodiments there isprovided a UE for enabling activation of a cell (or carrier). The UEcomprising a transceiver configured to receive a message from a networknode. The UE further comprising a processing circuitry configured todetermine if the received message contains an indicator indicatingwhether the UE shall perform activation of the cell upon configurationand, that being the case, the processing circuitry is configured toactivate the cell upon configuration of the cell.

According to yet another aspect of the present embodiments, there isprovided a network node for enabling activation of a cell (or carrier),the network node comprising processing circuitry and a transceiver. Theprocessing circuitry is configured to decide if a UE shall performactivation of a cell upon configuration and, that being the case, thetransceiver is configured to signal a message to the UE, the messagecontaining an indicator ordering the UE to activate the cell uponconfiguration of the cell.

An advantage achieved by the embodiments herein is to reduce the numberof glitches or interruptions.

Another advantage is to reduce the delay for the UE (or terminal) tostart communication with the network or network node using a cell.

Other advantages of the exemplary embodiments described in thisdisclosure will be presented in the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particulardescription of the example embodiments, as illustrated in theaccompanying drawings in which like reference characters refer to thesame parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe example embodiments.

FIG. 1 is an illustrative example of an aggregated bandwidth or a CAconfiguration

FIG. 2 is an illustrative example of configuration of cells/carriers toa terminal or UE

FIG. 3 is an illustrative example of another configuration ofcells/carriers to a terminal or UE;

FIG. 4 is a flowchart of method, performed in a UE, according toexemplary embodiments herein.

FIG. 5 is a flowchart of method, performed in a network node, accordingto exemplary embodiments herein.

FIG. 6 is a flowchart illustrating example operations, according to someexemplary embodiments presented herein;

FIG. 7 is a block diagram illustrating an example of a terminal or a UEaccording to an exemplary embodiment.

FIG. 8 is a block diagram illustrating an example of a network nodeaccording to an exemplary embodiment.

DETAILED DESCRIPTION

In the following description, for purposes of explanation and notlimitation, specific details are set forth, such as particularcomponents, elements, techniques, etc. in order to provide a thoroughunderstanding of the example embodiments. However, the exampleembodiments may be practiced in other manners that depart from thesespecific details. In other instances, detailed descriptions ofwell-known methods and elements are omitted so as not to obscure thedescription of the example embodiments. The terminology used herein isfor the purpose of describing the example embodiments and is notintended to limit the embodiments presented herein.

Briefly described, the exemplary embodiments disclosed herein are takingadvantage of that activation of a cell or a carrier is oftenwanted/desired to be performed as soon as the terminal or UE hasconfigured the cell. According to an embodiment, the terminal isconfigured to perform activation of a cell at, upon, or shortly after,configuration of the cell. This will reduce delay for the terminal tostart communicating with the network or network node using acell/carrier as well as reduce the number of glitches or interruptionsneeded to be performed. By said terminal is meant a mobile station or aUE or any user device capable to connect to or operate in a wirelesscommunication system such as LTE (Long Term Evolution) or LTE-Advancedor IMT-Advanced etc. Also when it is said network node it may be anynetwork node in the wireless communication system for example an evolvedNB (eNB) or NodeB, eNodeB or a radio base station.

FIG. 4 is a flow diagram depicting exemplary method steps performed bythe terminal or a UE in accordance. As shown, the method comprises:receiving 410 a message from the network node; determining 420 if thereceived message contains an indicator indicating whether the UE orterminal shall perform activation of the cell and, that being the case,activating 430 the cell upon configuration of the cell. The receivedmessage may be a Radio Resource Control (RRC) message that includes theindicator.

As an example, when the UE receives the message, the UE identifies ordetermines a value of the indicator received in the RRC message actsaccording to the result of the identification or determination.

In an exemplary embodiment involving the context of LTE, this could forexample be achieved by, the network node, including an indicator flag inRRC message used to configure (or “add”) a cell. Example 1 below showsan example realization of the indicator signalled in an informationelement (IE) of the RRC message or cell configuration message. Theindicator can be viewed as a flag. In Example 1 the indicator is calledactivateUponConfiguration and is comprised in IE SCellToAddMod-r10. Asshown the indicator may have a BOOLEAN value. As an example if theindicator (or flag) is set by the network node to true (or 1), thisindicates to the terminal or UE that it shall activate the cell uponconfiguration. If set by the network node to false (or 0) it isindicates to the terminal or UE that it shall not activate the cell uponconfiguration.

SCellToAddMod-r10 ::= SEQUENCE {  sCellIndex-r10 SCellIndex-r10, cellIdentification-r10 SEQUENCE {   physCellId-r10 PhysCellId,  dl-CarrierFreq-r10 ARFCN-ValueEUTRA  }  OPTIONAL, -- Cond SCellAdd radioResourceConfigCommonSCell-r10  RadioResourceConfigCommonSCell-r10OPTIONAL, -- Cond SCellAdd  radioResourceConfigDedicatedSCell-r10 RadioResourceConfigDedicatedSCell-r10 OPTIONAL, -- Cond SCellAdd2 activateUponConfiguration BOOLEAN,  ... }

Example 1 Example Realization of Indicator Signaled in CellConfiguration Message

According to an embodiment the UE or terminal is configured to respondto the network node with a RRC message confirming that activation of thecell has been performed.

It should be noted that the indicator may be optional to include,meaning that the network node may decide not to include it when sendingthe cell configuration message if deemed suitable. If not included, theterminal or UE may perform a default action, e.g. refrain from cellactivation upon cell configuration or perform cell activation upon cellconfiguration.

The opposite mapping of the values of the indicator is also possiblewhere the value false (or 0) indicates to the terminal or UE that itshall activate the cell upon configuration and if set by the network totrue (or 1) indicates to the terminal or UE that it shall not activatethe cell upon configuration, however the indicator may then have a moresuitable name.

FIG. 5 is a flow diagram depicting exemplary method steps performed bythe network node in accordance with previously described embodiments.The method comprising: deciding 510 if a terminal or a UE shall performcell activation upon configuration and, 520, that being the case,sending/signalling a message to the UE, the message containing anindicator ordering the UE to activate the cell upon configuration. Themessage may be a RRC message containing an indicator flag as explainedabove in relation to Example 1. The network node may further beconfigured to receive a confirmation from the terminal or UE confirmingthat cell activation has been performed.

The network node has therefore the freedom to decide if the terminal orUE shall, activate a cell upon configuration of that cell or not.Whether the network node wants the terminal to do so or not may dependon the scenario.

According to an exemplary scenario, the network node requests theterminal to activate a cell as soon as, or shortly after, or upon thecell or carrier has been configured in the terminal. In this contextcarrier aggregation is considered wherein the terminal maybe configuredwith a subset of cells offered by the network and the number ofaggregated cells may change dynamically based on e.g. terminal trafficdemand, type of service used by the terminal, system load etc. Asexplained before, the UE or terminal has one primary cell, PCell andzero or more secondary cells (SCells). Activation may be performed forSCell(s) and not necessarily for the PCell. The activation provides thepossibility to fulfil data rate needed at any given time. Activationtherefore provides the possibility to keep multiple cells configured foractivation on an as-needed basis.

If, for example, high throughput and low delay are considered importantthe network node maybe configured to indicate, through signalling, thatthe terminal shall perform cell activation upon cell configuration. Thismeans that the configured cell(s) will be available early forcommunication and therefore the delay is reduced and throughputincreased.

According to another example, if low power consumption is consideredimportant the network node maybe configured to indicate, throughsignalling, that the terminal shall not perform cell activation uponcell configuration. As an example, in LTE if the terminal has a cellactivated the terminal is required to monitor the Physical DownlinkControl Channel (PDCCH) of that cell which will consume terminal batterypower. If the network node intends to configure a cell for a terminalbut use it for data traffic at a later point in time, the network nodemaybe configured to indicate to the terminal that the terminal shall notperform cell activation upon cell configuration. Unnecessary power wasteof having the cell activated but not used can thereby be avoided.

Several alternatives for signalling/sending/transmitting saidindicator(s) will now be described in some examples.

According to an exemplary embodiment, the indicator maybe broadcastedfrom the network node. Different network nodes may broadcast differentvalues of this indicator. It may even be so that different cells offeredby the one node are broadcasting different values of this indicator. Anadvantage of broadcasting the indicator is that all terminals or UEswhich read/receive and/or decode the same broadcast channel will use thesame value. Another advantage of this alternative is that signallingoverhead may be small. If per terminal control is not important thissignalling alternative may be feasible.

According to another exemplary embodiment, an indicator istransmitted/signalled to the terminal from the network node, when theterminal performs initial access to the cell/network. This allows thenetwork to signal/transmit/send different indicator values to differentUEs. In case not all UEs are capable of performing cell activation uponcell configuration it may be necessary for the network node to signaldifferent values to different UEs. It will with this signallingalternative also be possible to have terminal specific/dedicatedsignaling which may, for example, be used by the network node to deliverdifferent quality of service for different UEs. For example, the networknode may indicate to a high priority terminal to perform cell activationupon cell configuration while a low priority terminal shall not. Anotherscenario is that the network node is configured to take intoconsideration performance regarding, for example, delay, and throughputand power consumption of the terminal when deciding which value toindicate to a terminal. If low delay and high throughput is consideredimportant for one terminal the network node may indicate to thatterminal that it shall perform cell activation upon cell configuration.While for another terminal, or the same terminal in another situation,low power consumption may be more important and the network node maytherefore indicate to the terminal that it shall not perform activationupon configuration.

As mentioned earlier, the network node may be configured to signal/sendthe indicator on a per need basis. For example, if a terminal initiallydoes not require high throughput and may not be configured with carrieraggregation the network node may therefore refrain from signalling thisindicator to this terminal. If the terminal's data traffic situationlater changes it may be suitable for it to be configured with multiplecarriers. At this later stage the network node may then send theindicator to the terminal indicating that the terminal shall performcell activation upon cell configuration.

Also this alternative allows for terminal specific/dedicated indicatorswhich bring the benefits as described in the previous exampleembodiment. On top of terminal specific indicators this signallingalternative also allows to change the indicator depending on the currentsituation, i.e. it can be changed over time. If the network node hasfirst signalled that a terminal shall perform cell activation upon cellconfiguration it may at a later stage be signalled the opposite if thelater situation dictates so.

According to another exemplary embodiment the eNB or network node isconfigured to signal the indicator in the same message, or in a compoundmessage, as the message which orders cell configuration. This signalingalternative is flexible as the network node may control if a terminal orUE shall perform cell activation upon cell configuration each time acell is configured. With this signalling alternative the network node oreNB may send/signal one message containing orders for configurations ofmultiple cells while only order activation upon configuration of asubset of these multiple cells. One example use case for this is whenthe network node orders configuration of multiple cells in a proactivemanner while currently only a subset of these cells shall be used forcommunication as dictated, for example by the terminal's current trafficsituation, and therefore the terminal shall (only) perform activationupon configuration on that subset of cell(s).

Also this alternative allows for terminal specific/dedicated indicatorsand situation dependent indicators which bring the benefits as describedearlier.

According to yet another exemplary embodiment, a combination of multiplesignalling alternatives is supported. In other words, multiple of theabove mentioned signalling alternatives may be supported. The terminalor UE may be configured to have different priorities for the differentsignalling alternatives. One foreseen alternative is that the belowpriority order is used where the value 1) indicates highest priority andthe value 4) the lowest priority:

-   -   1) Indicator signaled/transmitted in cell configuration message    -   2) Indicator signaled/transmitted on demand    -   3) Indicator signaled/transmitted during initial access    -   4) Broadcasting of indicator

It should be mentioned that some delay may be allowed from the time whenthe message ordering configuration of a cell is received by the terminaluntil the terminal have carried out the configuration. When herein isreferred to the time of configuration it should be appreciated that thistime may refer to the time when the terminal:

-   -   1. has successfully decoded the message ordering configuration        of the cell. The benefit of this alternative is that the cell        gets activated early. However, for some terminal architecture        the cell may not be able to reach the activated state before it        has completely been configured.    -   2. is configured to perform the cell configuration. As it was        explained in the background section the terminal is according to        current LTE specification given a window of 20 ms from that the        order for configuration is received until the terminal must have        carried out the cell configuration. It should be mentioned that        this value 20 ms is currently under discussion in 3GPP and may        be changed. One terminal may be faster in configuring a cell        while another terminal may be slower. The benefit of this        alternative is that the terminal is configured to activating a        cell as soon as the cell has been configured. A high end        terminal may be able to perform cell configuration faster than a        low end terminal and therefore the high end terminal can benefit        from performing activation earlier than the low end terminal.    -   3. is configured to respond with the        RRCConnectionReconfigurationComplete message. One of the        benefits foreseen with this alternative is that the network node        will know when the terminal has performed the activation of the        cell, which may be wanted in some situations.

According to an embodiment, the time of activation is an offset time ofthe time of configuration. The reason for this offset is that theterminal may need some time from that a cell has been configured untilthat the cell can be activated. For example, the terminal may berequired to successfully receive the newly configured cell's controlchannels before the cell can be activated and the terminal may need sometime to tune its receiver to successfully receive the control channelsof the newly configured cell. Therefore the offset may be used to ensurethat the terminal has completed all tasks necessary to performactivation of the newly configured cell.

It may be so that not all UEs are able to perform cell activation uponcell configuration depending on capabilities of a UE. For example, someUEs may need to perform measurements, monitor control channels, tune theradio to receive synchronization channels for a non-negligible timebefore the cell can be activated. In this exemplary embodiment theterminal indicates to the network if it is capable of performing cellactivation upon cell configuration as described in the above sections.Hence, the network node may consider the capability of a terminal whendeciding which value the indicator shall have or whether the indicatorshall be signaled or not.

As an example, to a terminal capable of cell activation upon cellconfiguration the network node may indicate that the terminal shallperform cell activation upon cell configuration.

As an example, to a terminal not capable of cell activation upon cellconfiguration the network node may indicate that the terminal shall notperform cell activation upon cell configuration or the network mayrefrain from sending the indicator. A non-capable terminal may ignorethe value indicated by the network, i.e. even if the indicator indicatesto a non-capable terminal that it shall perform cell activation uponcell configuration the terminal ignores the indicator.

There are several benefits of cell activation upon cell configuration.First, if the terminal is configured to activate a cell uponconfiguration of the cell there is no need for the network node to sendto the terminal an order for activation to render the cell activated.Note also that for such an activation command the terminal may need torespond with an acknowledgement confirming the reception of theactivation order. Both these messages may therefore be avoided.

Secondly, in case cell activation is achieved by an order for activationsent to the terminal by the network node, it may need to be sent to theterminal after the terminal has successfully configured the cell and theterminal has responded to the network with an acknowledgment, e.g. anRRCConnectionReconfigurationComplete message in LTE.

In case the terminal or UE performs cell activation upon cellconfiguration the terminal or UE will be configured to perform only oneRF retuning. Compare this to the case when the terminal first performscell configuration, upon which the terminal will in some cases perform aRF retuning, and later at cell activation another RF retuning is needed.If the terminal performs cell activation upon cell configuration theterminal will only perform one RF retuning and hence one glitch. As aglitch may affect other cells in the terminal than the cell which isactivated/deactivated and configured/deconfigured for the terminal,possibly the terminal's PCell, it important to reduce the number ofglitches.

FIG. 6 depicts example operations, according to some exemplaryembodiments presented herein. As shown, the terminal is configured toreceive 600 an order for cell configuration from a network node. Asshown, different alternatives are possible upon reception of the order.For each alternative it is determined whether or not the received ordercontains an indicator.

If an indicator is received in an activation command e.g. aconfiguration command (or a configuration message) 601, the terminaldetermines whether the indicator indicates that the terminal shallperform activation of the cell upon configuration 606. If so, theterminal activates the cell 608 upon configuration, otherwise, it doesnot 607.

If, instead, an on-demand indicator is received 602, the terminaldetermines whether the indicator indicates that the terminal shallperform activation of the cell upon configuration 606. If so, theterminal activates the cell 608 upon configuration, otherwise, it doesnot 607

If, instead, an indicator is received during initial access 603, theterminal determines whether the indicator indicates that the terminalshall perform activation of the cell upon configuration 606. If so, theterminal activates the cell 608 upon configuration, otherwise, it doesnot 607.

If, instead, an indicator is broadcasted 604, the terminal determineswhether the broadcasted indicator indicates that the terminal shallperform activation of the cell upon configuration 606. If so, theterminal activates the cell 608 upon configuration, otherwise, it doesnot 607.

If no indicator is received in the order, a default behaviour may beperformed 605, to activate the cell upon configuration or not as shownin FIG. 6.

It should be noted that the exemplary embodiments herein are notrestricted to the different scenarios described in relation to FIG. 6.For example, the presence of the indicator in the message received fromthe network node may per see be enough for the UE to activate the cellupon configuration of the cell. In another example, if the indicator isabsent or is not received from the network, the UE does not activate thecell.

FIG. 7 is an example configuration of a UE or terminal 700 according tosome of the example embodiments presented herein. The example UE 700 isshown comprising processing circuitry 730, radio circuitry 710 Rx/Tx.The UE 700 may further comprise a memory (not shown) and at least oneantenna (not shown) connected to Rx/Tx. The radio circuitry may compriseRF circuitry and baseband processing circuitry (not shown). Inembodiments, some or all of the functionality described above as beingprovided by mobile communication devices or other forms of wirelessdevice may be provided by the processing circuitry 730 executinginstructions or a computer program 750 stored on a computer-readablemedium of a computer program product 740. Alternative embodiments of theUE may comprise additional components responsible for providingadditional functionality, comprising any of the functionality identifiedabove and/or any functionality necessary to support the exampleembodiments described herein.

It should be appreciated that the processing circuitry (or any otherhardware and/or software unit configured to execute operations and/orcommands) of the UE may be configured to perform the previouslydescribed embodiments.

In summary, the UE or terminal 700 is configured to enabling activationof a cell at, or shortly after, configuration of the cell/carrier. Theterminal or UE 700 comprises the transceiver circuitry 710 configured toreceive/obtain/acquire, a message from a network node; the processingcircuitry 730 is configured to determine if the received message containat least one indicator indicating to the terminal/UE if/whether theterminal shall perform activation of a cell and that being the base theprocessing circuitry 730 is configured to activate the cell uponconfiguration of the cell. The processing circuitry 730 configured mayfurther be configured to identify or determine a value of at the atleast one indicator and further configured to act as a result of theidentification or determination.

As previously described, the received message may be a RRC messagecontaining an indicator flag corresponding to the indicator. Suchindicator flag may be part of an IE, as shown in previously describedExample 1. Also, the UE 700 may further be configured to respond to thenetwork node with an RRC message confirming that activation of the cellhas been performed.

Other operations performed by the UE have already been described andneed not be repeated.

FIG. 8 is an example configuration of a network node 800 (eNB or eNodeBor NodeB) according to some of the example embodiments presented herein.The example network node 800 comprises processing circuitry 830, amemory (not shown), radio circuitry 810 Rx/Tx or transceiver, and atleast one antenna (not shown) connected to Rx/Tx. The radio circuitrymay comprise RF circuitry and baseband processing circuitry (not shown).In embodiments, some or all of the functionality described above asbeing provided by the processing circuitry 830 executing instructions ora computer program 850 stored on a computer-readable medium of acomputer program product 840. Alternative embodiments of the networknode 800 may comprise additional components responsible for providingadditional functionality, comprising any of the functionality identifiedabove and/or any functionality necessary to support the exampleembodiments described herein.

It should be appreciated that the processing circuitry (or any otherhardware and/or software unit configured to execute operations and/orcommands) of the network node may be configured to perform thepreviously described embodiment.

In summary, the network node comprises the transceiver circuitry 810which is configured to decide if a terminal or UE shall perform a cellactivation and, that being the case, the transceiver 810 is configuredto send/signal at least one indicator to the terminal indicating if theterminal shall perform cell activation. The indicator is sent in amessage ordering the UE to activate the cell. The message may be a RRCmessage including an indicator flag as previously described. Also, thenetwork node 800, by means of the transceiver 810, may be configured toreceive a confirmation from the UE e.g. a RRC message confirming thatactivation of the cell has been performed. As previously described, thenetwork node may broadcast the message or send a message during initialaccess of the UE to the cell.

Other operations performed by the network node have already beendescribed and need not be repeated.

The description of the example embodiments provided herein have beenpresented for purposes of illustration. The description is not intendedto be exhaustive or to limit example embodiments to the precise formdisclosed, and modifications and variations are possible in light of theabove teachings or may be acquired from practice of various alternativesto the provided embodiments. The examples discussed herein were chosenand described in order to explain the principles and the nature ofvarious example embodiments and its practical application to enable oneskilled in the art to utilize the example embodiments in various mannersand with various modifications as are suited to the particular usecontemplated. The features of the embodiments described herein may becombined in all possible combinations of methods, apparatus, modules,systems, and computer program products. It should be appreciated thatthe example embodiments presented herein may be practiced in anycombination with each other.

It should be noted that the word “comprising” does not necessarilyexclude the presence of other elements or steps than those listed andthe words “a” or “an” preceding an element do not exclude the presenceof a plurality of such elements. It should further be noted that anyreference signs do not limit the scope of the claims, that the exampleembodiments may be implemented at least in part by means of bothhardware and software, and that several “means”, “units” or “devices”may be represented by the same item of hardware.

The various example embodiments described herein are described in thegeneral context of method steps or processes, which may be implementedin one aspect by a computer program product, embodied in acomputer-readable medium, including computer-executable instructions,such as program code, executed by computers in networked environments. Acomputer-readable medium may include removable and non-removable storagedevices including, but not limited to, Read Only Memory (ROM), RandomAccess Memory (RAM), compact discs (CDs), digital versatile discs (DVD),etc. Generally, program modules may include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types. Computer-executableinstructions, associated data structures, and program modules representexamples of program code for executing steps of the methods disclosedherein. The particular sequence of such executable instructions orassociated data structures represents examples of corresponding acts forimplementing the functions described in such steps or processes.

1. A method performed in a user equipment, UE, for enabling activationof a cell, the method comprising: receiving a message from a networknode; determining if the received message contains an indicatorindicating whether the UE shall perform activation of the cell; andactivating the cell upon configuration of the cell if it is determinedthat the received message contains an indicator indicating that the UEshall perform activation of the cell.
 2. The method of claim 1, whereinthe received message is a radio resource control, RRC, messagecontaining an indicator flag corresponding to said indicator.
 3. Themethod of claim 2, further comprising responding to the network nodewith an RRC message confirming that activation of the cell has beenperformed.
 4. A method performed in a network node for enablingactivation of a cell, the method comprising: deciding if a userequipment shall perform activation of a cell; and signaling a message tothe UE, the message containing an indicator ordering the UE to activatethe cell upon configuration of the cell if it is decided that the userequipment shall perform activation of the cell.
 5. The method of claim4, wherein the message is a radio resource control, RRC, messagecontaining an indicator flag corresponding to the indicator.
 6. Themethod of claim 5, further comprising receiving a RRC message from theUE confirming that activation of the cell has been performed.
 7. Themethod of claim 4, comprising signaling the message containing theindicator one of in a broadcast message and during initial access of theUE to the cell.
 8. A user equipment, UE, for enabling activation of acell, the UE comprising: a transceiver configured to receive a messagefrom a network node; processing circuitry configured to determine if thereceived message contains an indicator indicating whether the UE shallperform activation of the cell; and the processing circuitry beingconfigured to activate the cell upon configuration of the cell if it isdetermined that the received message contains an indicator indicatingthat the UE shall perform activation of the cell.
 9. The UE of claim 8,wherein the received message is a radio resource control, RRC, messagecontaining an indicator flag corresponding to said indicator.
 10. The UEof claim 9, wherein the UE is further configured to respond to thenetwork node with an RRC message confirming that activation of the cellhas been performed.
 11. A network node for enabling activation of acell, the network node comprising; processing circuitry; and atransceiver; the processing circuitry is configured to decide if a userequipment, UE, shall perform activation of a cell; and the transceiveris configured to signal a message to the UE, the message containing anindicator ordering the UE to activate the cell upon configuration of thecell if it is decided that the UE should perform activation of the cell.12. The network node of claim 11, wherein the message is a radioresource control, RRC, message containing an indicator flagcorresponding to the indicator.
 13. The network node of claim 12,wherein the transceiver is further configured to receive a RRC messagefrom the UE, confirming that activation of the cell has been performed.14. The network node of claim 11, wherein the transceiver is configuredto signal the message containing the indicator one of in a broadcastmessage and during initial access of the UE to the cell.
 15. The methodof claim 5, comprising signaling the message containing the indicatorone of in a broadcast message and during initial access of the UE to thecell.
 16. The method of claim 6, comprising signaling the messagecontaining the indicator one of in a broadcast message and duringinitial access of the UE to the cell.
 17. The network node of claim 12,wherein the transceiver is configured to signal the message containingthe indicator one of in a broadcast message and during initial access ofthe UE to the cell.
 18. The network node of claim 13, wherein thetransceiver is configured to signal the message containing the indicatorone of in a broadcast message and during initial access of the UE to thecell.